May is Healthy Vision Month, as well as Ultraviolet Awareness Month. The two go hand-in-hand; one way to maintain healthy vision is by protecting your eyes from ultraviolet light. With that in mind, consider these facts about ultraviolet light:
- Ultraviolet light falls on the electromagnetic radiation spectrum between visible light and X-rays; its wavelength is shorter than visible light, so most people and animals cannot see UV light (although some are able to). At the shorter end of the spectrum of UV radiation it starts to cross into X-ray radiation.
- There are four major types of UV radiation from the longest wavelength (closest to visible light) to the shortest wavelength (closest to X-rays): Ultraviolet A (UVA), Ultraviolet B (UVB), Ultraviolet C (UVC), and extreme Ultraviolet (EUV). Most UV rays that pass through the atmosphere are UVA, but there are some UVB. UVC and EUV are absorbed by the atmosphere through the ozone layer.
- Ultraviolet light is not all bad. Some exposure is good for the development of Vitamin D, which helps strengthen bones and strengthen the immune system. Shorter wavelengths of UV radiation, such as UVC, kill germs and are used for disinfecting surfaces in places like butcher shops and surgical rooms.
- However, overexposure to UV light has many bad side effects. UVB creates more damage than UVA, which is why when you shop for sunglasses you want sunglasses that protect from both UVA and UVB wavelengths. Too much UV radiation damages DNA, toughens skin, and causes eye damage. Also, UV damage builds over time, so the more often you protect your eyes from UV rays, the less damage you will have in later years of life.
- Plastic absorbs UV rays better than transparent glass; however, many glass surfaces, such as windows, lenses, and windshields, can be coated with a layer that absorbs UV rays. The best coatings protect from 100% UV rays, and protect from all wavelengths, including the longest wavelength of UV rays (known as UV400).
- Blacklights emit UVA rays, but the wavelength and amount of radiation emitted is not enough to cause damage. However, UV lamps used in tanning beds do cause considerable amounts of damage.
Protecting your eyes from UV light is just one way to prevent eye health problems like cataracts and maintain healthy vision. For other ways to improve or maintain healthy vision, check out our articles on the best foods for your eyes and eye care tips from last year’s Healthy Vision Month!